Wristbands can be used to identify individual persons wearing them. Typically wristbands have been cut from paper, plastic, or other bendable sheet type of material in the form of a strip. The strip can then be rolled to encircle a limb of the person, most typically the individual's wrist. Various fasteners or adhesives can be applied to maintain the physical presence of the wristband on the person. Techniques for fastening range from glue on paper wristbands to plastic or metal locking mechanisms used for higher security applications. Or, the band itself may include various types of cutout features so that when encircling the limb of a person a portion of the band can be inserted into the a receptacle slit or slot on the same band holding the band closed about the limb.
Common to all such applications is the ability to write, print, or otherwise mark the band with identifying information. In the least sophisticated applications of wristbands, a name or other identifying mark is simply written or printed on the band. Marking can be done by manually writing a name as with a pencil or pen, or information can be printed on a band by a machine such as a computer printer. In these most simple applications, the information is in a human readable form.
More recently bar codes, such as the UPC bar codes on most merchandise that we purchase have become a regular part of our every day life. Bar codes have also been added to wristbands in place of, or more typically in addition to human readable identifying information. Typically a special purpose band bar code writer applies a bar code to a wristband, in addition to other human readable information, such as a small photograph, a logo, or other human readable text. The bar code is typically designated a place on the band, allowing for other information to fill the remaining outside surface area of the band.
Bar coded wristbands are especially useful and helpful in institutional settings such as in hospitals. Such organizations generally utilize centralized or distributed computer systems that are amenable to providing at a minimum, individual person (patient) identification based on a scan of a patient wristband by a bar code scanner. Such identification can be particularly helpful to positively associate a particular patient to a particular hospital chart. Patient identification based on a scan of a patient wristband by a bar code scanner has also been used to automatically generate labels for patient specimens such as blood or urine. Patient identification has also been used to check and verify the dosage and types of medications administered to patients. Unfortunately, there are a series of problems associated with such bar coded wristbands. The problems are presented here in the context of a hospital setting, but as can be realized by others employing personal identification systems using bar coded wristbands. Many, if not all of these problems can be present in other institutional bar code wristband applications.
The first problem is that a linear bar code, a series of lines of varying thickness, a pattern familiar to most as similar to a merchandising product UPC code, is difficult to print on a wristband because of the width limitations of most typical bands. In one common scheme, a bar code is printed such that the lines of the bar code are roughly parallel to the limb encircled by the wristband (in the same direction of the arm, for example). Using this technique, the lines can be roughly as long as the narrow width of the strip that rolls into the wristband and the bar code can extend along the wristband, perpendicular to the limb. The problem with this bar code wristband arrangement is that the bar code then rolls around the wrist band. That is a bar code scanner trying to read such a bar code symbol views parts of the code at varying distances that can lead to depth field focus problems for the bar code reader optics package. To correct this problem, a nurse might have to try to flatten a portion of the bar coded section of wristband while attempting to scan it with a bar code reader. Or far worse, some of the code may be wrapped around the limb and not visible to the reader precluding a successful read. In this case, the wristband must typically be rotated and flattened to read it.
In response to this first problem, some linear bar coded wristbands use a 90 degrees rotated linear bar code such that the lines of the bar code are roughly perpendicular to the limb the band is wrapped around. In this case the length of the bar code (as determined by the number of lines the thickness of the lines, and the distance between them) is restricted to the narrow width of the wristband. While this solution generally exposes the entire code, thus solving the wrap around problem, such linear bar codes must be printed very small. A bar code scanner must have suitable optics to read such a small bar code and/or be placed very close to the bar code. Also, it is even more probable that the small bar code will not be in view thus requiring the person desiring to scan the code to rotate the wristband to bring the bar code into view for scanning. If the person to be identified is injured, sleeping, or otherwise immobilized, the task of rotating the wristband can be difficult. The possible consequences of manually rotating the band range from inconvenience and discomfort to worsening an injury.
Another problem with bar coded wristbands is that the code can become distorted, blurred, or otherwise unreadable. For example, a person tugging at the wristband or other physical damage to the wristband can cause pinching, creasing, tearing or other mechanical deformation. With a relatively weak plasticized band the code might become distorted under such conditions to a point where it is unreadable. Or, more likely a fluid, such as a bodily fluid, cleaning agent, or a medication, might spill on or be inadvertently rubbed against the code causing smearing, blurring, or even full or partial erasure of the code. Personal hygiene procedures in hospital settings, including showers and sponge baths can also degrade wristbands. When a patient ID wristband is damaged to a point where it needs to be replaced one or more nurses have to go to additional effort to reissue an ID wristband to the patient, thus wasting valuable hospital resources.
Another problem with bar coded wristbands is that they must be made small to be suitable for use with children and far smaller for infants. It can thus be seen that the above mentioned difficulties can become exacerbated when scaled to smaller pediatric wristbands.
Still another problem with bar coded wristbands is that there may be another copy of the same bar code printed on the wristband in a second location other than the wristband. For example, an identifying bar code on a patient wristband in a hospital can be identical to an identifying bar code on that patient's chart. In this case, a nurse desiring to conveniently scan a bar code might scan the bar code on the chart rather than the intended verification target bar code, the bar code on the patient's wristband. Some organizations solved this problem by adding characters to the identification string that distinguish the patient's wristband bar code from the bar code on the chart. This solution attempts to eliminate the possible error of incorrectly associating a patient with the wrong chart, thus incorrectly medicating or otherwise inadvertently treating the wrong patient. The Health Industry Bar Code (HIBC) provider application standard is an example of one such solution. The problem is that as previously presented, the space available for the bar code is barely sufficient for just the minimal amount of coded information simply to identify an individual person. Some institutions have eliminated the check characters in a misguided effort to make the bar code fit onto a wristband. However by doing this, they have actually increased the likelihood of a misread.